Phases of Growth In Plants – Growth Rates

One of the most fundamental and obvious qualities of a living thing is growth. What exactly is growth? Growth is described as an irreversible permanent increase in the size of an organ, its components, or even a single cell. In general, growth is accompanied by metabolic processes (both anabolic and catabolic) that use energy. As a result, leaf expansion is considered growth. How would you explain the expansion of a piece of wood in water?

Growth Rate in Plants 

Growth is defined as an organism’s permanent, irreversible rise in size. This characteristic is seen in all species and is accompanied by a number of metabolic processes. In plants, seeds germinate and grow into new seedlings, which eventually mature into adult plants. Plants continue to grow indefinitely.

Growth is the most basic feature of all living organisms. It is a permanent and irreversible metabolic process. Every living species, whether plants, animals, birds, or insects, goes through the process of expanding in size as it grows.

Plants have the remarkable capacity to grow continuously throughout their life cycle. Meristems are specialized cells that carry out the complete process of plant growth and development.

Plants are necessary for all life on Earth. They are significant because plants absorb CO2 from the atmosphere and create oxygen. Furthermore, plants serve as the foundation of the food web by manufacturing their own food through the use of light, water, carbon dioxide, and other substances. As a result, they are referred to as producers or autotrophs. Trees, vines, and bushes are examples of autotrophs on land. Autotrophs, commonly known as algae, may be found in the ocean’s top layers. One of the numerous functions that autotrophs give is erosion protection. Erosion occurs when the power of water, wind, or ice washes away soil layers that are required to guard against severe weather events such as thunderstorms or hurricanes.

The following are major elements influencing plant growth

• Temperature: As the temperature rises, growth accelerates.
• Light: Light intensity, duration, and quality all have an impact on various physiological processes that occur in plants.
• Water: Water is necessary for plant development. They thrive in adequate amounts of water. They even respond to water scarcity.
• Plant Growth Regulators: Auxin, cytokines, gibberellins, and other plant growth regulators are used to control plant growth.
• Soil Nutrients: Plants require a sufficient amount of nutrients to flourish properly. Plant development is influenced by the quality and amount of nutrients.

Phases Of Growth In Plants 

• Plants, like animals and people, increase in height and growth through time.
• But how do plants develop? How do the flowers and fruits of a tree appear and fall on a regular basis?
• All of these periodic occurrences in plants, from the zygote stage to the fully developed plant, occur in a systematic manner and are referred to as growth and development.
• Let us learn more about plant growth and its phases in this article.

Meristematic or formative, elongation, and maturity are the three stages of growth. We can better comprehend this by looking at a seed. We already know that the tips of roots and shoots develop continuously and are hence meristematic. The cells in this area have a lot of protoplasm and big nuclei. The cells nearby reflect the elongation growth phase. New cell walls, vacuoles, and other structures are formed in this area. The region immediately after the elongation phase indicates the maturation phase, during which the cells reach their maximum size.

Meristematic or formative

The meristematic zone of a plant’s root consists of meristematic cells that are continually proliferating and isodiametric (with no gaps between the cells); cells in the meristematic zone have abundant protoplasm with a big and prominent nucleus. These cells have primary cell walls that are thin and made of cellulose. These cells are linked by white plasmodesmata.

The cells in this area of the plant continue to divide rapidly. A big nucleus is typical of the plant’s meristematic zone. The cells present in plants promote the first phase of growth. Every plant has them in its roots and branches.

Elongation 

The cells that are present close to meristematic cells are in the elongation phase. These cells elongate due to the growth of the vacuole within the cell, and this zone is known as the zone of elongation. Cell expansion and the production of new cell walls occur in cells during the elongation phase. Cells undergo modifications such as bigger vacuoles.

Maturity

The cells detected after the elongation zone are in the maturation phase and have reached their maximal size. They stop dividing once they reach the maturity stage. The zone of maturation is seen as a mass differentiation phase in plants when cells specialize to execute specific roles.

Knowing these three phases of cell growth, we can state that the distinct processes that occur in these phases are cell division, cell expansion, and cell differentiation. The first two phases cause the plant to grow larger, while the third phase causes the cells to mature. During differentiation, the cells’ protoplasm and cell wall undergo structural modifications.

Growth Patterns in Arithmetic and Geometry

Rate of Plant Growth 

It is measured in terms of growth per unit of time. Plants have two forms of growth:

Plant Arithmetic Growth

When plant cells divide, two cells are generated from a single cell. One of these two cells continues to divide, while the other differentiates and forms various structures. The former cell splits and generates two new cells, one of which continues to divide and one of which is differentiated. We now have two differentiated cells from a single cell. Similarly, a pattern is developed, and the plant gradually grows in size. This phase can be represented as a linear graph with regard to plant height vs. time.

The formula for calculating Arithmetic Growth curve outcomes is as follows:

L_t = L₀+ rt

Plant Geometric Growth 

In this situation, the cell divides by mitotic division, resulting in the formation of two cells. Both cells divide once more to generate two new cells. As a result, the number of cells doubles at each step. The number of cells will be in the range of 2, 4, 8, 16, 32, 64, and so on. Unlike arithmetic growth phases, no cell differentiation occurs here. The cell growth rate is quite high here in the geometric phase, and when it reaches its peak, it slows down and then becomes stable owing to several limiting forces. The geometric growth of plants may be represented by the following S-shaped graph, with a Sigmoid Growth curve in plants.

• Lag Phase – This is the slower phase of cell division.
• Log Phase – The growth is quite quick in this phase, which is also known as the exponential phase. A sharp curvature forms.
• Stationary Phase – The growth is steady or stationary and becomes constant in this phase.

The formula that represents this Sigmoid Growth Curve is as Follows:

W_t = W₀ * e^rt

Growth is a natural process, and unlike humans, plants develop in a variety of ways. The process that helps plants develop to their maximum potential is the process that plants conduct in the presence of sunshine, water, and organic molecules in order to create nourishment in the form of ATP. This, in turn, aids the plant’s growth and supplies energy to all of its cells.

FAQs on Plant Growth Rates 

Question 1: Why is plant growth important?

Answer: 

Plants are necessary for all life on Earth. They are significant because plants absorb CO2 from the atmosphere and create oxygen. Furthermore, plants serve as the foundation of the food web by manufacturing their own food through the use of light, water, carbon dioxide, and other substances.

Question 2: What are the three phases of plant development?

Answer: 

Learn the Three Plant Growth Stages Now to Become a Better Gardener

• Stage of development (Seed germination)
• Stage of vegetative growth (Growth)
• Stages of reproduction, blooming, and fruiting

Question 3: What features of plant growth are there?

Answer: 

Plant Growth Characteristics-The plant grows indefinitely. Because of the presence of ‘meristems’ in their bodies, plants have the remarkable capacity to grow forever throughout their lives.

• Plant growth may be measured.
• Meristematic Stage
• The phase of Extinction.
• Maturation Period
• Arithmetic Development.
• Geometric Development.

Question 4: What is a plant’s growth rate?

Answer: 

By replacing total plant leaf area for total biomass in the usual RGR calculation, the plant growth rate may be calculated as the relative increase in leaf area over time.

Question 5: What exactly is plant growth and development?

Answer: 

Plant Growth and Development is the study of the control and coordination of processes in cells, organs, and/or entire plants, such as changes in gene expression in response to environmental variables like climate change.